Admission control for variable spreading gain CDMA cellular system with imperfect power control and shadowing

Variable spreading gain (VSG) CDMA is the prime transmission scheme for supporting multiple services for the next generation cellular systems. As different services have different quality of service and data rate requirements, admission control is essential in safeguarding the performance of different services in VSG-CDMA cellular systems in harsh wireless environment. In this paper, we propose an admission control scheme for multiple services VSG-CDMA cellular system in a practical multi-cell environment where there exist adverse effects due to imperfect power control and shadowing. Rather than with a fixed bound as in previous studies, the admission bound in our scheme is based on the probability distribution of total intra-cell power (P-in) and other-cell interference power (I-other). This is used to estimate the blocking probability by utilizing a simple and accurate approximation that incorporates the random nature of P-in and I-other. Evaluation of the impact of power control error to the mean and standard deviation of P-in and I-other, we performed and compared the blocking probability with fixed admission bound scheme in an integrated voice/data environment. Our work has enabled the calculation of the blocking probability and capacity of different mobility users having different power control errors under shadowing. Copyright (C) 2006 John Wiley & Sons, Ltd.